Why have violent intolerance and cultural exchange often occurred side by side? This is a question we face today, but one with long roots in history. In this class, we will attempt to answer this question by looking at Christian, Muslim, and Jewish communities in western Europe and Byzantium. We will explore specific episodes in depth: in medieval Spain, for example, we will see that Christian rulers threatened, fought, and fought alongside their Muslim counterparts, while also borrowing heavily from the cultural achievements of Muslim rulers. In Spain and beyond, we will examine the toleration of minority religious communities in Europe, the limits of these accommodations, and how and why religious toleration broke down. To the east, the Christians of the Byzantine Empire also had longstanding relationships with its Muslim and Jewish neighbors and subjects, and we will see how Byzantium's Roman inheritance and eastern Mediterranean location led it down a path distinct from western Europe's. Along the way, we will explore the implications of the constant sharing of texts, ideas, food, and luxuries, and thus explore the complex, dynamic interactions between power, knowledge, and identity in western Europe and Byzantium. This course does not presuppose any background knowledge of medieval or Byzantine history or the command of any language other than English, and students will be introduced to relevant material as the course progresses.